The biggest financial institution in Mexico left 24.1 million account holders without access to ATMs, its mobile app or in-store payments on Sunday.

BBVA México’s operating failures were first reported early in the day and continued for almost 20 hours until the late evening. Users were taken by surprise when they tried to take out cash, deposit money or make transfers and were declined. The newspaper El Universal reported that in-store payments were also affected.

“BBVA México informs all its users that we are seeing irregularities in our services. We are working to solve it as soon as possible and reactivate the operations that our users require. We apologize for the inconvenience,” the bank said at 11:13 a.m. after receiving complaints on social media.

One account holder detailed the issue on the BBVA México Twitter account. “The ATM did not deliver my cash. I checked the app and an incorrect failed connection message came up. I called BBVA and they said that in three hours they would finish with updates.”

Meanwhile, the owner of rival Banco Azteca, Ricardo Salinas Pliego, took the opportunity to advertise his company’s services. “Now that @BBVA_Mex’s system is not working, with the sole desire to help its customers I want to share a new @BancoAzteca App that has everything in one place, in addition to being easy to use it is very reliable, unlike Bancomer’s,” he wrote on Twitter.

BBVA México has 1,725 branches, 13,014 ATMs and 517,729 point of sale terminals, according to figures released in May.

With reports from El Universal, Aristegui Noticias and El Economista